Diagnostic value of microbiome biomarkers of the periodonite microbiome in patients with the association of chronic periodontitis and diabetes mellitus type 2

The place of high-tech methods of molecular biology in clinical laboratory diagnostics of various diseases and the development of a system of biomarkers as an important component of diagnostic research is currently attracting the closest attention of the scientific community. In this paper, an attempt is made to use high-tech metagenomic analysis to solve problems that arise due to the high frequency of association of periodontal diseases with systemic pathology, in particular, with type 2 diabetes mellitus. The aim of the study was to determine the taxonomic and metabolic features of the microbiome of periodontal tissues in periodontal diseases associated with type 2 diabetes mellitus, as a model of the ratio of local and systemic effects of periodontal pathogenic bacteria. The study included 16S shotgun sequencing of bacterial DNA as part of biological material from periodontal pockets/dentoalveolar furrows of 46 people - 15 patients with chronic periodontitis associated with type 2 diabetes mellitus, 15 patients with chronic periodontitis unrelated to systemic pathology, as well as 16 healthy people in the control group, followed by bioinformatic processing of the data obtained. The obtained data allowed us to establish the taxonomic features of the periodontal microbiome in the association of chronic periodontitis with type 2 diabetes mellitus, which included the predominance of representatives of the families Prevotellaceae and Spirochaetaceae in its composition. The features of metabolic processes in periodontal tissues with the participation of the microbiome were also revealed, which consisted in an increase in the exchange of cysteine and methionine against the background of a decrease in the metabolism of pyrimidine, methane, sphingolipids, and the synthesis of fatty acids, which are of diagnostic value in assessing the condition of patients with type 2 diabetes mellitus.

[The medical social work with individuals of elderly and senile age with total loss of teeth]

The article substantiates the necessity in applying the complex approach to handle medical social problems of patients in elderly and senile age suffering of complete absence of teeth conditions the relevance of developing medical and social work with this contingent. In the complex management of patients receiving dental orthopedic care, professional social workers apply medical, psychological, pedagogical and social measures targeted to maintain their actual health. It is demonstrated that such activities can be implemented within the framework of wide network of social service organizations in cooperation with dentists.

[Filifactor alocis and its role in the etiology of chronic periodontitis]

The review is devoted to the analysis of modern ideas about the role of bacteria Filifactor alocis in the etiology of chronic periodontitis. The study of these bacteria, discovered in 1985, is complicated by the difficulty of their detection with cultural methods. According to modern researches, the bacteria F.alocis with good reason can be included in the red complex of periodontal pathogens as the most important pathogens of chronic periodontitis. F.alocis is a synergist of such a key pathogen Porphyromonas gingivalis, as well as a frequent satellite of Fusobacterium nucleatum and, somewhat less frequently, Aggregatibacter actinomycetemcomitans. F.alocis is practically not found in healthy people (except for smokers), with a high frequency accompanies the aggressive course of periodontal disease, and also recorded in endodontitis. Due to the ability to participate in the metabolism of arginine, expressed protease activity, a wide range of virulence factors, F.alocis not only colonizes the periodontal tissues, but also significantly affects the formation of the community of periodontal microorganisms (including viruses), contributing to their invasion of epithelial tissues. F. alocis has a number of unique properties, including resistance to oxidative stress conditions in the home defeat, induction of apoptosis of epithelial cells, extracellular matrix degradation of periodontal tissues, activation of proinflammatory cytokines formulation in sites of its presence, suppression of protective reactions of neutrophilic granulocytes, inhibition of the process of complement activation.

[Clinical evaluation of the innovative concept of teeth saving]

AIM

To evaluate the effectiveness of the innovative concept of dental medical technologies in patients with resected (amputated) roots of teeth with and without periodontal diseases.

MATERIAL AND METHODS

Of the 516 examined patients with periapical destructive foci of infection of various genesis, 4 clinical groups of 24 people were randomly formed: (1) with a diagnosis of apical periodontitis of incisors, canines or premolars with individual milled transdental implants made of zirconium dioxide; (2) patients with a similar diagnosis and concomitant periodontitis of moderate severity with the same implants; (3) patients with periapical destructive process of molars without periodontitis with the same implants. Control group (4) included patients with similar diagnoses with resection of the root apex without implantation. Patients of the study groups were operated in accordance with the developed clinical protocols, including the manufacture and installation of individual transdental implants with fixation in the postoperative period, developed within the framework of tooth-preserving technologies of immobilizing structures.

RESULTS

The reinforcement of teeth with resected roots with transdental implants together with immobilization of these teeth in the postoperative period restores the biomechanical characteristics of the tooth 2.7 times more effectively. However, there is a slight change in the mobility of the operated teeth in an earlier period (after 3 months), which is associated with the resorption of the bone-replacing agent used to fill the intraoperative defect and with the defective formation of bone tissue. The values of peritelomeric 6 months after the operation differ from the control by 1.4 units only.

Interrelation of Cardiovascular Diseases with Anaerobic Bacteria of Subgingival Biofilm

Aims:

The aim of this study is to study the colonization of subgingival biofilm (SGB) with periodontopathogenic bacteria species and endothelium-dependent vasodilation in patients with coronary heart disease and concomitant periodontitis.

Subjects and Methods:

Forty-five patients with cardiovascular diseases (CVDs) were examined – 28 women (62%) and 17 men (38%) aged 53–76 years, including 15 patients with acute myocardial infarction (AMI), 15 patients with exertional angina (pectoris), and 15 patients with chronic periodontitis (CP) without CVD. Dental and cardiological health conditions were determined, a biochemical blood test was conducted, endothelium-dependent vasodilation in the brachial artery was measured, and DNA of periodontopathogenic bacteria in SGB was detected.

Results:

A reliable interrelation between the colonization of SGB with periodontopathogenic bacteria and development of AMI was established. In AMI patients, the frequency of Porphyromonas gingivalis, Tannerella forsythia, and Aggregatibacter actinomycetemcomitans detection was significantly higher than in the group of participants without cardiovascular disease. The presence of P. gingivalis and A. actinomycetemcomitans in patients with CP directly correlated with severity of periodontal tissue destruction. Endothelium-dependent vasodilation in the brachial artery moderately correlated with patient's cardiological condition (r = 0.3284), biochemical markers of atherosclerosis development (r = 0.6465), and frequency of P. intermedia detection in periodontal pockets (r = 0.3828).

Conclusions:

Periodontal status in patients with AMI is characterized by unsatisfactory and poor hygiene, increased indices of bleeding on probing, and periodontal pocket depth in comparison to groups of patients with angina pectoris and CP without cardiovascular pathology.

[Short dental implant biomechanics in the mandible bone tissue]

The aim of the study was to assess the stress-strain state of «short dental implant - lower jaw bone tissue» system in the its osseointegration area under different stress options, of an experimentally developed bone tissue model. Using the finite element analysis method, we investigated a three-dimensional model of an implant with 5.0 mm diameter and 6.5 mm height integrated into the quasi-elastic model of the lower jaw segment with a total deformation modulus of 14 400 MPa and a Poisson's ratio of 0.24 for the cortical layer, for the spongy layer, the general deformation module of 0.2 MPa, Poisson's ratio 0.4. The values of equivalent stresses according to the Genki-Mises criterion for the implant body amounted to 50-76 MPa in the cervical region from the end and inner sides of the implant interface and along the upper edges of the thread edges in the upper third of the implant. Minimum values of 0.1-20 MPa are distributed over the implant body from its cervical part to the top in the lower 2/3. The equivalent von Mises stresses in the bone at the joints of the threaded implant part are minimal - 5-15 MPa. Values of shear stresses in the bone - 2 - 3 MPa, normal vertical stresses - up to 5-13MPa, main tensile stresses - up to 20 MPa, compressive stresses - up to 30-40 MPa. Thus, installing this implant in such model, should not occur irreversible deformations. In our opinion, the structural stability is ensured by the bone tissue features architectonics within 3 mm of the cortical layer, where the maximum stress is redistributed in the future throughout the cortical bone, which can expand the indications for short dental implants use, especially in patients with a limited alveolar bone volume.

[Prosthodontic treatment of edentulous patients with postoperative mandibular defects of oncological origin]

The aim of the study was clinical and bacteriological approbation of improved obturator dentures with soft lining. The study involved 116 patients (68 females and 48 males aged 47-78) with edentulous jaws and side palatal defect of oncological origin. Improved elastic obturator maxilla dentures in patients with palatal defects proved to have better stability and provides better comfort effectively preventing inflammation of prosthetic bed soft tissues.

Metagenomic Analysis of Gingival Sulcus Microbiota and Pathogenesis of Periodontitis Associated with Type 2 Diabetes Mellitus

Biofilm of the gingival sulcus from 22 patients with type 2 diabetes mellitus and periodontitis, 30 patients with periodontitis not complicated by diabetes mellitus (reference group), and 22 healthy volunteers without signs of gingival disease (control group) was studied by quantitative PCR. Quantitative analysis for the content of P. gingivalis, T. forsythia, A. ctinomycetemcomitans, T. denticola, P. intermedia, F. nucleatum/periodonticum, and P. endodontalis in the dental plaque was performed with a Dentoscreen kit. The presence of other bacterial groups was verified by metagenomic sequencing of the 16S rRNA gene to evaluate some specific features of the etiological factor for periodontitis in type 2 diabetes mellitus. Specimens of the Porphiromonadaceae and Fusobacteriaceae families were characterized by an extremely high incidence in combined pathology. The amount of Sphingobacteriaceae bacteria in the biofilm was shown to decrease significantly during periodontitis. Metagenomic analysis confirmed the pathogenic role of microbiota in combined pathology, as well as the hypothesis on a possible influence of periodontitis on the course and development of type 2 diabetes mellitus.